Well Picard was pretty Picard like in Generations, got his assed kicked too although he was probably affected by family events. First Contact was Picard getting through some emotional baggage left over by what the Borg did to him so he wasn't in his right mind and went ape shit on them. Insurrection he was affected by the planet's rings causing him to act in a more youthful way then he might have done and we all know what youthful (laughing with a blade in his heart) Picard was like. Nemesis he was affected by being confronted by a youthful version of himself and in some ways had felt violated that some part of him was stolen and that he could actually be capable of the same tings Shinzon did. The only out of character thing was that constipated look on his face when Shinzon died in front of him.